f Canada: the Great
Lakes are in the center of the whole eastern and more thickly settled
half of North America, and they bind the Canadian and Middle Western
people together. On the south, the provinces meet the apex of that of
the Gulf Plains, and the Mississippi unites them. To the west, they
merge gradually into the Great Plains; the Missouri and its tributaries
and the Pacific railroads make for them a bond of union; another rather
effective bond is the interdependence of the cattle of the plains and
the corn of the prairies. To the east, the province meets the Alleghany
and New England Plateaus, and is connected with them by the upper Ohio
and by the line of the Erie Canal. Here the interaction of industrial
life and the historical facts of settlement have produced a close
relationship. The intimate connection between the larger part of the
North Central and the North Atlantic divisions of the United States will
impress any one who examines the industrial and social maps of the
census atlas. By reason of these interprovincial relationships, the
Middle West is the mediator between Canada and the United States, and
between the concentrated wealth and manufactures of the North Atlantic
States and the sparsely settled Western mining, cattle-raising, and
agricultural States. It has a connection with the South that was once
still closer, and is likely before long to reassert itself with new
power. Within the limits of the United States, therefore, we have
problems of interprovincial trade and commerce similar to those that
exist between the nations of the Old World.

Over most of the Province of the Lake and Prairie Plains the Laurentide
glacier spread its drift, rich in limestone and other rock powder, which
farmers in less favored sections must purchase to replenish the soil.
The alluvial deposit from primeval lakes contributed to fatten the soil
of other parts of the prairies. Taken as a whole, the Prairie Plains
surpass in fertility any other region of America or Europe, unless we
except some territory about the Black Sea. It is a land marked out as
the granary of the nation; but it is more than a granary. On the rocky
shores of Lake Superior were concealed copper mines rivaled only by
those of Montana, and iron fields which now[129:1] furnish the ore for
the production of eighty per cent of the pig iron of the United States.
The Great Lakes afford a highway between these iron fields and the coal
areas of the Ohio V